In the field of microsurgery, a reusable surgical instrument is assembled in well-known conventional fashion where the cutting blade is mounted to traverse a specific pattern guided by elements of the surgical instrument. The blade and associated guide elements are mounted in somewhat remote location with respect to the hands of the surgeon. A conventional feature of the surgical instrument is a staple cartridge which is used only once.
The cartridge is a generally elongated rectangular plastic body which includes a channel formed longitudinally in the elongated body. The channel is a guide for the surgical blade which is secured on the surgical instrument. The structure of the instrument and cartridge which are well-known in the industry include a plurality of small staples aligned in the cartridge parallel with the guide channel. After the blade makes its cut and other necessary surgical operations are performed, a remote actuator causes each side of the incision to be stapled together for obvious reasons.
The particular structure for manipulating the blade and actuating the staple operation is not a part of this invention. It is well-known in the industry and there is no need to describe the same.
Due to the minute structure involved in the surgery for which this invention is made, there may be as many as fifty or more staples on each side of a two inch incision which are actuated simultaneously to close the wound. The staples are pushed by drivers through the tissues around the wound and against an anvil on the surgical instrument. The anvil deflects the points of the staples into clasping position. Assembling of the drivers into the cartridge and maintaining them in place to drive the staples into the tissues is a labor intensive chore.
The present system for mounting the staple drivers in pockets in the cartridge is to form a plastic tree having aligned branches with staple drivers integrally formed on one end of each of the aligned branches. The already-formed conventional cartridge is placed in a fixture and the tree bearing the staple drivers is hand manipulated to place the drivers adjacent the entrance to pockets in the cartridge. Each driver is pressed into the pocket in the cartridge by the fingers of the assembler. Separation of the individual drivers from the branch of the tree on which it is mounted is accomplished by a flexing of the branches of the tree manually to break off the staple drivers. Then, a hand-manipulated blade or prong is used to press each staple driver down into the cassette to near the pocket opening on the opposite side of the cassette.
Unfortunately, the finger operation of pressing each driver into a pocket, the flexing of the branches which also tilts the drivers and the subsequent pressing from the hand operated prongs can misalign some of the drivers within the pockets.
The size of the pockets and the periphery of the drivers may have a slight variation due to the minute structure involved and the fact that both the cartridge and the staple drivers are formed of thermoplastic resin, could cause some play in the assembly and that can cause an alignment problem. Particularly, an inversion of the cartridge could result in some drivers being displaced from their pockets due to gravity and/or impacts during assembly and packaging, and even during the mounting of the replacement cartridge with the surgical instrument. Obviously, if the staple driver is not in place, there will be no staple at that point in the incision.
This invention solves the problem of assuring driver alignment in the pockets, accelerates the assembling operation and provides a block or lock mechanism to prevent the unintentional displacement of staple drivers from pockets in the cartridge after initial assembly.